Patents by Inventor Aimo Sahila

Aimo Sahila has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6645588
    Abstract: Conventional coating compositions have the disadvantage of being insufficiently coatable and having an unsatisfactory environmental stress cracking resistance. Now a coating composition has been found which has both good coating processability and environmental stress cracking resistance. It comprises a multimodal ethylene polymer, which contains from 80 to 100% by weight of ethylene repeating units and from 0 to 20% by weight of C3-C10 &agr;-olefin repeating units, has a density of between 0.915 g/cm3 and 0.955 g/cm3, and is a blend of at least a first ethylene polymer having a first average molecular weight and a first molecular weight distribution and a second ethylene polymer having a second average molecular weight, which is higher than said first average molecular weight, and a second molecular weight distribution, said blend having a third average molecular weight and a third molecular weight distribution.
    Type: Grant
    Filed: July 24, 2000
    Date of Patent: November 11, 2003
    Assignee: Borealis Technology Oy
    Inventors: Leif Leiden, Markku Asumalahti, Jari Aarila, Laila Rogestedt, Hans-Bertil Martinsson, Bengt Hagstrom, Aimo Sahila
  • Patent number: 6090893
    Abstract: The invention relates to polyethylene compositions containing 85-99.5 weight % of component A, which is a linear (co)polymer of ethylene having a bimodal weight distribution, and 0.5-15 weight % of component B having a unimodal molecular weight distribution. Component A is 40-60% by weight of a low molecular weight component (A1) having a weight average molecular weight between 5,000 and 50,000 g/mol, and a molecular weight distribution Mw/Mn between 2.5 and 9 and 60-40% by weight of a high molecular weight component (A2) having a weight average molecular weight between 300,000 and 900,000 g/mol, and a molecular weight distribution M/w/Mn between 4.5 and 12. Component B is a linear ethylene polymer having a molecular weight between 150,000-600,O00 g/mol and an average molecular weight which is higher than the average molecular weight of component (A1) but lower than the average molecular weight of component (A2) and a density controlled within the range of 910-960 kg/m.sup.3.
    Type: Grant
    Filed: June 16, 1997
    Date of Patent: July 18, 2000
    Assignee: Borealis Polymers Oy
    Inventors: Ali Harlin, Aimo Sahila, Veli Kilpelainen, Anders Nymark
  • Patent number: 6031027
    Abstract: A method of compounding a multimodal, preferably a bimodal polymer composition comprising a low molecular weight ethylene polymer and a high molecular weight ethylene polymer is described. The composition is compounded during a relatively long time at a low temperature which lies in a narrow temperature range including the melting point of the low molecular weight ethylene polymer. More particularly, the polymer composition is compounded, without addition of a beat transfer medium, in a temperature range from about 10.degree. C. below to about 10.degree. C. above the melting point of the low molecular weight ethylene polymer during a time of more than 10 seconds. The viscosity ratio between the ethylene polymers in said temperature range preferably is from about 5:1 to about 1:5.
    Type: Grant
    Filed: March 26, 1999
    Date of Patent: February 29, 2000
    Assignee: Borealis Polymers OY
    Inventors: Arne Syre, Carl-Gustaf Ek, Aimo Sahila, Svein Eggen, Rune Nygaard, Ilka Vaara, Kristen Kjeldsen
  • Patent number: 5684097
    Abstract: A process for producing polyethylene compositions in the presence of a catalytic system of ethylene polymerizing catalyst and cocatalyst in a multistage continuous reaction sequence consisting of successive liquid phase and gas phase polymerizations is disclosed. In the first step of the process, ethylene and optionally hydrogen and comonomer are polymerized in a first loop reactor in a low boiling hydrocarbon medium in the presence of ethylene polymerizing catalyst and cocatalyst. The reaction mixture is then removed and then transferred to a second loop reactor where polymerization is continued by addiing ethylene, hydrogen and optionally inert hydrocarbon, comonomers and cocatalysts. Thereafter, the reaction mixture is removed from the second loop reactor along with an essential part of the reaction medium and transferred to a gas phase reactor where polymerizing is continued in the presence of added ethylene and optionally hydrogen, comonomers and cocatalysts to form an end product.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: November 4, 1997
    Assignee: Borealis Polymers OY
    Inventors: Ari Palmroos, Ali Harlin, Antero Ahvenainen, Jouni Takakarhu, Aimo Sahila
  • Patent number: 5194533
    Abstract: The invention relates to a new bis(trialkylsilyl) chromate of the formula ##STR1## where n is approximately 1-2. Such a compound can be prepared by causing a corresponding silyl halide to react with silver chromate. The product is especially suitable for the polymerization and copolymerization of ethylene, the formed polymer having a high molar mass and a wide molar mass distribution.
    Type: Grant
    Filed: April 23, 1991
    Date of Patent: March 16, 1993
    Assignee: Neste Oy
    Inventors: Aimo Sahila, Hilkka Knuuttila, Bill Gustafsson